Field of the Invention
This invention relates to mounts for mounting optical sights on firearms.
It is known that it is desirable to be able to make adjustments to an optical sight on a firearm so that with the reticle of the sight centered on the target the projectile from the firearm will hit the target in spite of the effect on the projectile of wind and/or gravity as it travels to the target. The adjustments, in effect, cause the user to aim the barrel, for example, to the left of the target, to counteract the effect of wind from the left, and above the target, to counteract the effect of gravity, when he centers the reticle on the target. These adjustments are often referred to as azimuth (or windage) and elevation.
The desired adjustments may be achieved by moving the reticle within the sight while maintaining constant the dispositional relationship of the barrel and sight as a whole. Alternatively, the sight may be moved, as a whole, relative to the barrel. The former manner of achieving the adjustment has the advantage that the mount serving to mount the sight on the firearm may be simple and rugged. It has the disadvantage that the movable reticle makes the sight more expensive to manufacture and prone to damage.
The latter manner of achieving the adjustment, namely, moving the sight as a whole, has the advantage that the sight has a fixed reticle which makes the optical sight less expensive to manufacture and less prone to damage by blows and the like in combat conditions. However, the mount is more prone to damage because it has to contain mechanisms for achieving very fine adjustments. Those skilled in the art know that the maximum range of azimuth adjustment may be as small as 10 minutes limit to limit and that the increments of adjustment may be as small as 15 seconds. Also, the elevation adjustment may have a maximum range of 1 degree and the desirable increments of adjustment may be as small as 1/2 minute.
Those skilled in the art know that it is highly desirable that the mount provides repeatability, that is, that the selected adjustments be exactly retained until they are intentionally changed, despite forces encountered in successive firings and despite blows and other maltreatment in combat conditions.